Truck stalls out when put in reverse. Parts replaced.....
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I found this forum post interesting. First page is ok but the 2nd and 3rd get better.
https://www.jeepforum.com/forum/f13/.../735568?page=4
https://www.jeepforum.com/forum/f13/.../735568?page=4
Thread Starter
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Registered User
Joined: Nov 2018
Posts: 14
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Some more info...
I ran across some service records from the previous owner that showed something worth mentioning. About a year ago they had “transmission lines” and a “salvage” transmission cooler. That’s all that was in the description. I called the previous owner and she stated she thought it was a leak. Not positive. They owned it a little over a year and said the stalling in reverse developed during their ownership. It didn’t always do this. I know that often we can cause our own issues when performing repairs and thought this was worth mentioning.
Secondly, I have learned how to almost keep the truck from stalling in reverse. If I throw it in reverse and quickly jump out to neutral then back to reverse fairly quickly it stumbles pretty hard and doesn’t idle perfectly but keeps running around 400-500 rpms. I towed a 750lb trailer to my folks house and had an interesting experience. I was backing up my driveway which isn’t steep but it has a pretty good incline so I was in reverse going uphill. I had to floor the throttle and I wasn’t sure the truck was going to make it up the driveway. It almost came to a stop. It wasn’t slipping but it was like I couldn’t get any power. RPM’s wouldn't raise. It was odd for sure.
I ran across some service records from the previous owner that showed something worth mentioning. About a year ago they had “transmission lines” and a “salvage” transmission cooler. That’s all that was in the description. I called the previous owner and she stated she thought it was a leak. Not positive. They owned it a little over a year and said the stalling in reverse developed during their ownership. It didn’t always do this. I know that often we can cause our own issues when performing repairs and thought this was worth mentioning.
Secondly, I have learned how to almost keep the truck from stalling in reverse. If I throw it in reverse and quickly jump out to neutral then back to reverse fairly quickly it stumbles pretty hard and doesn’t idle perfectly but keeps running around 400-500 rpms. I towed a 750lb trailer to my folks house and had an interesting experience. I was backing up my driveway which isn’t steep but it has a pretty good incline so I was in reverse going uphill. I had to floor the throttle and I wasn’t sure the truck was going to make it up the driveway. It almost came to a stop. It wasn’t slipping but it was like I couldn’t get any power. RPM’s wouldn't raise. It was odd for sure.
Last edited by Bliggity; Dec 9, 2018 at 08:57 PM.
Legend
Joined: Feb 2005
Posts: 8,058
Likes: 184
From: Fort Worth, TX
oh boy. Sounds like you have a real winner.
Let me check the hydraulic flows, but I'm pretty sure if there is a loss of pressure to the reverse segment, it can lose output drive AND seize the input drive.
Let me check the hydraulic flows, but I'm pretty sure if there is a loss of pressure to the reverse segment, it can lose output drive AND seize the input drive.
Champion
Joined: Jul 2011
Posts: 4,895
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From: Gilbert, Arizona
If the previous owner only had it a year they had a lemon and wanted to dump it now you own it sorry.
That's always the problem with a used auto why are they selling it.
That's always the problem with a used auto why are they selling it.
Last edited by 98DAKAZ; Dec 11, 2018 at 09:23 AM.
Professional
Joined: Aug 2018
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I have the exact same fusible link in my 3.7 it's definitely not stock,, possibly a recall repair.
Last edited by XSubaruJeepDude; Dec 11, 2018 at 12:38 AM.
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Joined: Oct 2018
Posts: 451
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From: Midwest
I'm not up on Dodges so I may be off base here, but...
If the IAC were the problem, I would think it would be a problem regardless of the transmission setting. Anything else forward of the transmission would be the same, it wouldn't affect just one specific gear. Anything behind the transmission would also affect all gears. That the truck doesn't act up when put into reverse when the rear wheels are off the ground points to a loss of pressure here as well, since there is no resistance in the transmission caused by the rear wheels not moving. When the rear wheels are on the ground, there is going to be more resistance inside the transmission from trying to turn the wheels but not being able to.
What is odd here is that it is killing the engine, which implies that the torque converter is locking when the trans is shifted to reverse. The torque converter always spins the same direction regardless of what gear the transmission is in. Any problems in the trans should not be transmitted to the engine, because the torque converter's whole purpose is to allow the engine to spin freely while the transmission is not moving. It's almost like there is a short in the transmission which causes the TC to lock up when it's shifted into reverse. If this is the case, taking the rear end off the ground would not affect it because the wheels are being allowed to spin right off. But, if the rear wheels are on the ground and the TC locks, then it's like stopping a manual trans car while it's in gear without pushing in the clutch. It is enough to shut down the engine. I'd wonder if you repeated the rear wheels off the ground test again, if you'd be able to kill the engine by shifting to reverse then holding the brakes on hard. As the rear brakes are weaker than the front, you wouldn't necessarily have had enough pressure on the rear wheels to keep them from spinning when you put the brake on enough to shift. On magnethead's thinking that the input drive is seizing, the TC does drive the trans pump that should be on the input shaft. I wouldn't think that the pump seizing would be enough to keep the TC from spinning, but I guess it's possible.
Hope some of this helps.
If the IAC were the problem, I would think it would be a problem regardless of the transmission setting. Anything else forward of the transmission would be the same, it wouldn't affect just one specific gear. Anything behind the transmission would also affect all gears. That the truck doesn't act up when put into reverse when the rear wheels are off the ground points to a loss of pressure here as well, since there is no resistance in the transmission caused by the rear wheels not moving. When the rear wheels are on the ground, there is going to be more resistance inside the transmission from trying to turn the wheels but not being able to.
What is odd here is that it is killing the engine, which implies that the torque converter is locking when the trans is shifted to reverse. The torque converter always spins the same direction regardless of what gear the transmission is in. Any problems in the trans should not be transmitted to the engine, because the torque converter's whole purpose is to allow the engine to spin freely while the transmission is not moving. It's almost like there is a short in the transmission which causes the TC to lock up when it's shifted into reverse. If this is the case, taking the rear end off the ground would not affect it because the wheels are being allowed to spin right off. But, if the rear wheels are on the ground and the TC locks, then it's like stopping a manual trans car while it's in gear without pushing in the clutch. It is enough to shut down the engine. I'd wonder if you repeated the rear wheels off the ground test again, if you'd be able to kill the engine by shifting to reverse then holding the brakes on hard. As the rear brakes are weaker than the front, you wouldn't necessarily have had enough pressure on the rear wheels to keep them from spinning when you put the brake on enough to shift. On magnethead's thinking that the input drive is seizing, the TC does drive the trans pump that should be on the input shaft. I wouldn't think that the pump seizing would be enough to keep the TC from spinning, but I guess it's possible.
Hope some of this helps.